1. Technical Field of the Invention
This invention relates to telecommunication systems. More particularly, and not by way of limitation, the invention is directed to a system and method of billing users of telecommunication services in a telecommunications network based on the reported traffic load in the network.
2. Description of Related Art
Wireless telecommunication networks are evolving from second generation (2G) circuit-switched networks to third generation (3G) packet-switched networks. A reference architecture for a 3G wireless network is being developed by the Third Generation Partnership Project (3GPP). The 3GPP network architecture uses the Session Initiation Protocol (SIP) developed by the Internet Engineering Task Force (IETF) for call setup signaling. Media is then transported through an existing IP network. The SIP standard is described in RFC 2543 which is hereby incorporated in its entirety by reference herein.
In a SIP network, users register their existence on a sub-network through a Call State Control Function (CSCF). Each user has a unique SIP ID which is an address which follows the user to different terminals. For example, when a user sits at his office desk, he can register himself as being at his desk. The desk phone sends a SIP REGISTER message with the user's unique SIP ID and the phone's hardware device ID to the CSCF so that it knows where to route the user's calls. The REGISTER message also contains a presence state that indicates the current status of the user. For example the user may designate that he is at his desk, but is currently not available.
The presence state in the REGISTER message is routed to a Presence and Instant Messaging (PIM) Server associated with the CSCF. The PIM server provides the user's presence state to other users on the network and also enables the user to monitor the presence state of other users. The user can determine the other party's presence state (for example, registered, not registered, busy, etc.) from a display such as a telephone or computer display at his desk before placing a call.
An originating user need not specify the exact destination address associated with the destination user. The 3GPP network uses aliases associated with particular users to automatically determine the identity of their registered terminals or devices, and to automatically format and deliver communications with the registered devices over an existing IP network. Thus, the 3GPP network architecture provides a centralized and independent communication control mechanism. For a registered user, the 3GPP network and associated elements keep track of the user's exact location and the identity of the user's registered terminal, and accordingly route and enable communication with that registered user over the existing IP network.
When billing the users for telephony services, providers have traditionally billed an amount equal to a billing rate (for example $0.10/minute) times the duration of the call. The billing rate has historically been adjusted during different periods of the day and week. For example, lower rates have typically been used for nights and weekends than the peak rate that is used during the workweek day. These adjustments in the billing rate have been made due to estimated changes in the traffic load on the network. Since the load is typically the heaviest during the workweek day, a higher rate is charged for calls during this period of time.
However, the traditional method of adjusting the billing rate relies on a gross estimate of the traffic load on the network based on historical averages of traffic loads at different times of the day. At any particular time, the actual traffic load may be lower or higher than the historical averages, and thus, the user may be charged at a rate that is either too high or too low for the actual network conditions. It would be advantageous, therefore, to have a system and method of billing users of telecommunication services in a telecommunications network based on the reported traffic load in the network at the time that the user places the call. The present invention provides such a system and method.